NCT04773873

Implant Retained CAD-CAM Ceramic Crowns

Randomized Controlled Clinical Trial (RCT) of Implant-retained Monolithic Chairside-made CAD-CAM Hybrid Abutment Single Crowns

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 90 (actual)
• Sponsor: Susanne Scherrer · Academic / Other
• Sex: All
• Age: 25 Years – 70 Years
• Healthy volunteers: Accepted

Summary

Newly available ceramic CAD-CAM blocs containing a screw channel for chairside-made crowns to be adhesively cemented to a TiBase abutment and screw-retained to an implant are appealing to the clinician, considering the time efficiency (one appointment) and overall lower costs as no dental laboratory is involved. The hypotheses are that the biological (BOP, PD, PCR, implant bone level) and mechanical outcomes (fracture, loss of retention, wear) are equivalent to implant screw-retained Porcelain-Fused-to-Metal (PFM) crowns over a 5 year observation time.This RCT will provide key information as to the cost/benefit, suitability and/or limitations of these chair-side hybrid-abutment crowns in the posterior region.

Detailed description

This RCT involves the University of Geneva Dental School and four private practices for which the Geneva Hospital Ethic Committee's approval is required. Patients in need for replacement of single unit posterior teeth will be recruited at the Dental School as well as in the 5 private practices based on specific selection criteria. Patients will be randomly assigned to a restorative group using a computer-generated random number table for allocation. The CAD-CAM blocs containing a screw channel for implant-retained chairside-made single-unit hybrid-abutment crowns are 1) Lithium-disilicate glass-ceramic (e.max CAD) (G1) and 2) feldspath-ceramic infiltrated by polymer (Enamic) (G2). The CAD-CAM crowns are adhesively cemented to titanium base abutments (Ti-base) and screw-retained to Titanium implants (Straumann Standard Plus) in the premolar (RN) and molar region (WN). Controls are screw-retained PFM crowns (G3). The number of crowns in each group is N=30 (15 molars and 15 premolars) which gives a total of 90 crowns for this study. Participants are recalled after 1 week-10 days after crown insertion (baseline, T0) and then yearly during 5 years (T1-T5). Digital X-Rays are taken at T0, T1, T3 and T5 with repositionable individual resin bite registrations.

Conditions

• Prosthesis Survival

Interventions

Type	Name	Description
DEVICE	PFM Crowns on gold coping cast-on	Classic impressions are taken by the operators and sent to one and same laboratory who will deliver all the screw-retained PFM restorations. The crowns will be made using a gold coping cast-on synOcta gold abutment (Ceramicor) for wide (WN) or regular (RN) neck
DEVICE	hybrid abutment lithium disilicate crown	Intraoral digital impression with respective scanbodies (Sirona) for Cerec OmniCam or Cerec Bluecam over the chosen TiBase. Cerec CAD designing (operator) and CAM milling (Cerec MCXL) of single crowns with perforated blocs (e.max CAD). crystallization/ characterization/ glaze firing for the e.max CAD crown using an oven with specific firing programmes for e.max CAD. Adhesive cementation steps of the ceramic crown onto the TiBase
DEVICE	hybrid abutment ceramic polymer infiltrated crown	Intraoral digital impression with respective scanbodies (Sirona) for Cerec OmniCam or Cerec Bluecam over the chosen TiBase. Cerec CAD designing (operator) and CAM milling (Cerec MCXL) of single crowns with perforated blocs (Enamic). Surface polishing with rubber polishers. Adhesive cementation steps of the ceramic crown onto the TiBase

Timeline

• Start date: 2015-01-01
• Primary completion: 2023-12-08
• Completion: 2023-12-08
• First posted: 2021-02-26
• Last updated: 2023-12-11

Locations

1 site across 1 country: Switzerland